\begin{abstract}
In this report we study Cross-Site Request Forgery (CSRF), a common exploit used to attack websites.
We present the most well known defenses against this attack and explain how each one works.
Moreover, We conducted an analysis on the top 100,000 websites, as rated by alexa.com, as to which 
defense they implement to counter any CSRF attacks and present the results.  To meet this end we 
implemented a tool that crawls the web, parses HTTP headers and HTML body of each site to deduct which 
defense is employed. 
\end{abstract}
